feat(datasource/golang-version): add golang-version datasource (#13291)

* Implement feature

* Make timestamp UTC

* Fix timestamp format

* Apply suggestions from code review

Co-authored-by: Michael Kriese <michael.kriese@visualon.de>

* Changes after code review

* Changes after code review

* Fix test

* Changes after code review

* Update lib/datasource/golang-version/index.ts

* Fixed coverage

* Changes after code review

* Fix tests after merge

Co-authored-by: Rhys Arkins <rhys@arkins.net>
Co-authored-by: Michael Kriese <michael.kriese@visualon.de>